docs: def _processCheckAuthResponse(self, response, server_url):
          """Process the response message from a check_authentication
          request, invalidating associations if requested.
          """
          is_valid = response.getArg(OPENID_NS, 'is_valid', 'false')
  
          invalidate_handle = response.getArg(OPENID_NS, 'invalidate_handle')
          if invalidate_handle is not None:
              logging.info(
                  'Received "invalidate_handle" from server %s' % (server_url,))
              if self.store is None:
                  logging.error('Unexpectedly got invalidate_handle without '
                              'a store!')
              else:
                  self.store.removeAssociation(server_url, invalidate_handle)
  
          if is_valid == 'true':
              return True
          else:
              logging.error('Server responds that checkAuth call is not valid')
              return False